A prior art generator of this type having more than middle capacity (private generator) will be described with reference to FIGS. 16(a) and 16(b).
The generator comprises an engine 1, a starter (actuation generator) 2, a generator (three-phase synchronous generator) 3, a power converter 4, a starter power supply (battery) 5, an actuation switch 6, a transmission unit 7 composed of a pulley 1G attached to a shaft of the engine 1, a pulley 2G attached to a shaft of the starter 2, a pulley 3G attached to a shaft of the generator 3, and a belt 8 entrained around the pulleys 1G, 2G, and 3G.
Actuation or starting of the generator is carried out in the manner that firstly the switch 6 is turned on for supplying a power from the power supply 5 to drive the starter 2. Secondly, a turning effect of the starter 2 is transmitted to the engine 1 via the transmission unit 7 for thereby starting the engine 1 which results in simultaneously starting the generator 3. Thirdly, the speed of rotation N of the generator 3 is increased to reach a speed of rotation N.sub.o where a predetermined value of alternating voltage can be issued from the power converter 4, whereby the actuation is completed. Fourthly, an alternating current power having a predetermined voltage with a predetermined frequency can be supplied to a load (not shown). The power converter 4 comprises a main circuit having switching elements composed of a plurality of transistors formed in bridge connection and a control circuit having a drive unit for supplying an ON-OFF signal to the main circuit for effecting inverting operation. The power generated by the generator 3 is stably converted to an alternating current power having a predetermined voltage value and predetermined frequency. After the starting operation of the engine 1 has been completed, the switch 6 is released.
Inasmuch as the prior art generator, as described above, requires the starter to be used exclusively for starting or actuating the engine, there causes such a problem that the generator unit is large and complex. At the same time, there is a problem of deterioration of reliability and maintenance of the generator unit caused by the trouble of the starter.